The Radiorenogram as a Measure of Renal Function

Abstract

Winter1has demonstrated the value of the radioisotope renogram as a screening test for unilateral renal disease. The test provides a graphic record of the serial radioactivity over each kidney after the intravenous injection of a test substance labeled with radioiodine. That record, in turn, gives evidence as to the renal vascularity, the tubular function, and the patency of the excretory tract for the respective kidney. Initially, labeled iodopyracet (Diodrast) was used as the test substance. Due to the fact that iodopyracet is concentrated by the liver, as well as by the kidney, errors of interpretation arose which discredited the radiorenographic procedure in the minds of some observers. However, the recently introduced radioactive-iodohippurate sodium (radio-Hippuran) has proved itself to be an agent which is accumulated only by renal tissue, and which is removed rapidly from the blood by the kidney.2 From the contour of the renographic curve, the